Crude polysaccharides extracted from successfully solid-state-cultured Trametes robiniophila (PST) showed cellular immunomodulatory and tumor-inhibitory activities in vivo. The different concentration of PST (100, 200, 400 mg kg -1 body weight) significantly enhanced immunity response in mice burden with Sarcoma 180 (S180) solid tumor. The results indicated that PST not only increased the macrophage phagocytosis and NO production, but also promoted lymphocyte proliferation and natural killer cell activity, and PST administration significantly inhibited tumor growth with the rate up to 60.9%. Interestingly, the most effective polysaccharides dosage on enhancing cellular immunity and inhibiting tumor was 200 mg kg -1 body weight each day. In conclusion, in vivo immunostimulatory and tumor-inhibitory activities of PST showed a non-dose-dependent manner, and suggested it could be used potentially in medicinal application.